Currently, there are few options for filtering phone calls other than programming an extension to ring at a specific place according to a specific schedule or manual selection. These options treat all callers in the same way. There is no simple way to direct calls differently depending upon who the caller is.
One known solution to the problem involves using a call direction system, such as Accessline™ to control where or whether a called party's phone rings at a specific time. However, this call direction has to be set up in advance, either through a schedule or by logging in to a system and directing calls on the fly. Call direction is easy if the called party has access to the Internet and enough time to plan accordingly. However, this solution is not practical if the called party is caught in traffic or on the way to a meeting. Furthermore, the called party could be driving to the meeting, having diverted calls to voice mail, when an invitee to the meeting are other important person is trying to reach the called party to cancel the meeting or provide important information.
Another known solution involves systems that can detect a caller ID and statically direct a missed call to a predefined mailbox based on that caller ID. These systems are limited to categorizing voicemail to a predefined mailbox, and none of the systems allow a call to be dynamically routed based on criteria from the called party's calendar or from any other similar input. Current systems have to be programmatically changed and the programming last indefinitely until the next programmatic change.